title: Modulation of basal and squamous cell carcinoma by endogenous estrogen in mouse models of skin cancer.
abstract: Patched1 heterozygous mice (Ptch1(+/-)) are useful for basal cell carcinoma (BCC) studies, being remarkably susceptible to BCC induction by ultraviolet or ionizing radiation. Analogously, skin carcinogenesis-susceptible (Car-S) mice are elective for studies of papilloma and squamous cell carcinoma (SCC) induction. We previously reported a striking effect of gender on BCC induction in Ptch1(+/-) mice, with total resistance of females; likewise, Car-S females show increased skin tumor resistance relative to males. Here, we investigated the protective role of endogenous estrogen in skin keratinocyte tumorigenesis. Control (CN) and ovariectomized Ptch1(+/-) or Car-S females were irradiated for BCC induction or topically treated with chemical carcinogens for SCC induction. Susceptibility to BCC or SCC was dramatically increased in ovariectomized Ptch1(+/-) and Car-S females and restored to levels observed in males. Remarkably, progression of initially benign papillomas to malignant SCC occurred only in ovariectomized Car-S females. We explored the mechanisms underlying tumor progression and report overexpression of estrogen receptor (ER)-alpha, downregulation of ERbeta and upregulation of cyclin D1 in papillomas from ovariectomized Car-S relative to papillomas from CN females. Thus, an imbalanced ERalpha/ERbeta expression may be associated with estrogen-mediated modulation of non-melanoma skin carcinogenesis, with a key role played by cyclin D1. Our findings underscore a highly protective role of endogenous estrogen against skin tumorigenesis by diverse agents in two independent mouse models of skin cancer.
authors.affiliation: Biotechnology Unit, Ente per le Nuove Tecnologie, l'Energia e l'Ambiente, CR-Casaccia, Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Mancuso
authors.forename: D
authors.initials: D
authors.lastname: Gallo
authors.forename: S
authors.initials: S
authors.lastname: Leonardi
authors.forename: M
authors.initials: M
authors.lastname: Pierdomenico
authors.forename: E
authors.initials: E
authors.lastname: Pasquali
authors.forename: I
authors.initials: I
authors.lastname: De Stefano
authors.forename: S
authors.initials: S
authors.lastname: Rebessi
authors.forename: M
authors.initials: M
authors.lastname: Tanori
authors.forename: G
authors.initials: G
authors.lastname: Scambia
authors.forename: V
authors.initials: V
authors.lastname: Di Majo
authors.forename: V
authors.initials: V
authors.lastname: Covelli
authors.forename: S
authors.initials: S
authors.lastname: Pazzaglia
authors.forename: A
authors.initials: A
authors.lastname: Saran
mesh_terms: D000818:Animals; D002280:Basal Cell Carcinoma / Q000378:metabolism* / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D002471:Cell Transformation, Neoplastic / Q000378:metabolism / Q000473:pathology; D019938:Cyclin D1 / Q000378:metabolism; D004195:Disease Models, Animal; D047628:Estrogen Receptor alpha / Q000378:metabolism; D047629:Estrogen Receptor beta / Q000378:metabolism; D004967:Estrogens / Q000502:physiology*; D005260:Female; D008297:Male; D051379:Mice; D009381:Neoplasms, Radiation-Induced / Q000378:metabolism / Q000473:pathology; D010052:Ovariectomy; D010212:Papilloma / Q000378:metabolism / Q000473:pathology; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D012878:Skin Neoplasms / Q000378:metabolism* / Q000473:pathology; D014466:Ultraviolet Rays
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; C000606240:Ptch1 protein, mouse; D011956:Receptors, Cell Surface; D019938:Cyclin D1